Zou, Hu;
Sui, Jipeng;
Saintonge, Amélie;
Scholte, Dirk;
Moustakas, John;
Siudek, Malgorzata;
Dey, Arjun;
... Zou, Siwei; + view all
(2024)
A Large Sample of Extremely Metal-poor Galaxies at z < 1 Identified from the DESI Early Data.
The Astrophysical Journal
, 961
(2)
, Article 173. 10.3847/1538-4357/ad1409.
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Abstract
Extremely metal-poor galaxies (XMPGs) at relatively low redshift are excellent laboratories for studying galaxy formation and evolution in the early universe. Much effort has been spent on identifying them from large-scale spectroscopic surveys or spectroscopic follow-up observations. Previous work has identified a few hundred XMPGs. In this work, we obtain a large sample of 223 XMPGs at z < 1 from the early data of the Dark Energy Spectroscopic Instrument (DESI). The oxygen abundance is determined using the direct T e method based on the detection of the [O iii]λ4363 line. The sample includes 95 confirmed XMPGs based on the oxygen abundance uncertainty; the remaining 128 galaxies are regarded as XMPG candidates. These XMPGs are only 0.01% of the total DESI observed galaxies. Their coordinates and other properties are provided in the paper. The most XMPGs have an oxygen abundance of ∼1/34 Z ⊙, a stellar mass of about 1.5 × 107 M ⊙, and a star formation rate of 0.22 M ⊙ yr−1. The two most XMPGs present distinct morphologies suggesting different formation mechanisms. The local environmental investigation shows that XMPGs preferentially reside in relatively low-density regions. Many of them fall below the stellar mass–metallicity relations (MZRs) of normal star-forming galaxies. From a comparison of the MZR with theoretical simulations, it appears that XMPGs are good analogs to high-redshift star-forming galaxies. The nature of these XMPG populations will be further investigated in detail with larger and more complete samples from the ongoing DESI survey.
| Type: | Article |
|---|---|
| Title: | A Large Sample of Extremely Metal-poor Galaxies at z < 1 Identified from the DESI Early Data |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-4357/ad1409 |
| Publisher version: | https://doi.org/10.3847/1538-4357/ad1409 |
| Language: | English |
| Additional information: | Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10186251 |
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